Arthropods such as cockroaches, carpet beetles, clothes moths, cigarette beetles, drug store beetles, fleas, wood destroying organisms, bed bugs, lice, house dust mites, etc. are known to infest furniture and other household objects. (This list does contain the entire list of affected arthropods). The most notorious of these, bed bugs, Cimex lectularius L., have been associated with humans for at least the past 3500 years (Panagio-takopulu). After a decline in bed bug populations in developed countries after World War II (Kruger 299, Gangloff-Kaufman and Schultz 2003), a resurgence of these blood sucking insects have been causing increasing problems (Pinto et al. 2007). Because these insects hide in cracks and crevices (Ursinger 1966), detection (Cooper and Harlan 2004), and control can be challenging. This is especially true when bed bug aggregations occur on beds, furniture, and other objects where the application of chemical pesticides may cause problems both for the pest control industry and for customers not willing to accept close contact with pesticides.
Thus a physical control method applied to the room contents should be useful as a tool, in the overall management of arthropod infestations as a supplement to crack and crevice insecticidal applications to potential harborages
Heat treatment of a whole room or building is currently used for control of Bed Bugs (Kells 2006, Pinto et al. 2007) as well as many other insects especially storage pests (Tang it al. 2007). Temperatures between 44 and 45 C (Doggett et al. 2006) have been cited repeatedly as lethal to bed bugs.
Heat treatments varying from whole structure to whole room to containerized treatments have been used by the pest control industry (Pinto et al. 2007) reportedly with positive results. However, the use of solar radiation as a heat source to kill bed bugs in encased mattresses reportedly did not provide control (Doggett et al. 2006) because the insects were able to move away from high temperature areas. Cost of the necessary equipment, the energy requirements, treatment duration, and other difficulties related to commercially available whole room and building heat treatments have created the need for an alternative localized heat treatment for the control of arthropod infestations.
This invention relates generally to a systematic method of heating objects to the lethal temperature of the infesting arthropod. Heating is a known method for controlling insects.
A method to heat entire structures is disclosed in U.S. Pat. No. 4,817,329. Generally, a region of the structure was subjected to hot gases for a sufficient time period to raise the host material temperature to the desired level and maintain the temperature until the insects perished. This heat treatment could be directed under ground. The entire structure was encased in insulation matt. This heating system was very costly, laborious and not economically feasible.
A later U.S. Pat. No. 5,058,313 describes an apparatus that includes the inspection of a structural wooden member within a structural wall; isolating the wooden member infected with insects; then positioning heat producing devices next to the isolated wood member on the outside wall. The heat producing device was activated and the isolated wooden member was heated sufficiently to kill a large number of insects in the wooden member. After one location was heated, the device was deactivated and moved to another location. Both convective and infrared heating systems were utilized. This system treated areas of walls and floors. It was unsuitable for oddly shaped objects and pieces of furniture.
Still further U.S. Pat. No. 6,141,901 describes a system of pest control of heating the effected area to the lethal temperature for the pest and maintaining this temperature for at least eleven hours. The CFM exchanges required 3-5 air changes per hour. While the heated air introduced in the treatment zone was at least 200 F. This system requires hot air that could deform wood (170 F) and requires a long time period (11 hours).
Still further U.S. Pat. No. 6,327,812 B1 discloses a system where ingress ducts are installed in windows and hot gas including ozone is pumped into the structure. Monitor probes are placed in strategic areas of the structure and the building's temperature is monitored. Exhaust gas from the structure is filtered to remove any organism remains. This system requires the heating of the entire structure at a high cost.
U.S. Pat. No. 6,892,491 B2 is a continuation of U.S. Pat. No. 6,327,812. Once again the entire structure is heated to up to 400 F. The main difference from the previous patent is that a negative pressure is created in the enclosure and the heated air carrying the harmful substances is passed through a filter to remove the harmful substances. This time the apparatus heats an entire structure under vacuum conditions at very high temperatures. U.S. Pat. No. 7,690,148 B2 is a continuation of U.S. Pat. No. 6,892,491. It is the same process except it includes the use for pests.